Pharmacokinetic and preliminary metabolic fate of navelbine in humans as determined by high performance liquid chromatography.

The pharmacokinetics and metabolism of Navelbine (NVB) were investigated in 20 patients by a specific high performance liquid chromatographic methodology allowing the monitoring of NVB, deacetyl-NVB, and N-oxide NVB. After the i.v. (15 min) administration of 30 mg/m2 of drug, blood and urine samples were collected for, respectively, 144 and 48 h. NVB is characterized by a three compartmental kinetics, with a Cmax of 1130 +/- 139 (SEM) ng/ml. The total body clearance and apparent volume of distribution, as defined by high performance liquid chromatography, are 1.26 +/- 0.09 liter/h/kg (48.6 +/- 4.1 liters/h/m2) and 75.6 +/- 9.2 liters/kg (2918.4 +/- 307.2 liters/m2). No metabolite could be detected in serum; the urinary excretion of NVB represented 11% of the administered dose. Deacetyl-NVB could be identified as a minor urinary metabolite when no N-oxide NVB appeared in the urine samples. Two additional peaks appeared in most of urinary chromatograms as trace amounts. Thus, the major pathway of NVB, as for other Vinca alkaloids, should be hepatic clearance, as biliary elimination and/or hepatic biotransformation.